Employee Stock Purchase Plan (Details)	1 Months Ended				12 Months Ended
	Oct. 30, 2014	Apr. 30, 2014	Oct. 30, 2013	Apr. 30, 2013	Dec. 31, 2013
Employee Stock Purchase Plan [Line Items]
Expected volatility				26.34%	34.30%
Expected term (in years)				6 months	4 years
Risk-free interest rate				0.15%	0.80%